1. ## Posterior probabilities

I know P(c1|x) = p(x|c1).p(c1)

I don't know how to calculate p(x|c1)

I am given 2 vectors in the form (x,y)

and a covariance matrix (2x2)

How do i calculate p(x|c1) from this?

2. By any chance is this a bivariate normal density?
If so, see Multivariate normal distribution - Wikipedia, the free encyclopedia